Winnie Mandela may have emerged as an anti-apartheid leader in South Africa during her ex-husband Nelson Mandela's imprisonment in 1963, but it took until 2013 -- as she turns 76 -- for her story to get the full Hollywood treatment.

In Winnie Mandela, Oscar winner Jennifer Hudson takes on the title role, portraying the iconic activist from the time she was 19 to 70 years old. Terrence Howard plays Nelson Mandela.

Though the film first premiered at the Toronto Film Festival in 2011, it will receive a proper theatrical release on Sept. 6 courtesy of RLJ Entertainment.

"I literally contemplated going home," Hudson tells The Hollywood Reporter, recalling her four-month stay in South Africa as she prepared for and filmed the project. During her research, Hudson called on locals to share their stories of Mandela and quickly became intimidated by the magnitude of her influence.

"Hearing them speak of her, some of them would break down crying. They would talk for hours and I'm like, 'Wow.' That intimidated me," says Hudson. "I literally gave myself a good talking to, like, 'OK, look, you are in this or you are not going to be in it. I don't even want to play with it -- it's nothing to take lightly.' "

Mandela has been portrayed on the small screen many times, including the 2010 BBC drama Mrs. Mandela (starring Sophie Okonedo), the 1997 TV film Mandela and de Klerk (with Tina Lifford) and the 1987 HBO film Mandela (starring Alfre Woodard). Hudson's portrayal is the first to hit the big screen and the first to focus solely on the former Mrs. Mandela. This month, Mandela's story will return to the Toronto Film Festival with Justin Chadwick's Mandela: Long Walk to Freedom, starring Idris Elba and Naomie Harris.

Hudson, who achieved fame as a competitor on American Idol, thought it was high time for the world to see Winnie's story in the spotlight.

"I [was] just reading the script and I [was] like, 'Oh my God, I cannot believe that I am almost 30 years old and I’m just now learning about Winnie, other than her name and that she’s Nelson Mandela’s wife,' " says Hudson. "That’s all we ever heard, and then when I read the script, I thought, 'How come we don’t know her? Why don’t we know this about her? Or her contributions to the struggle?' "

Rather than feel threatened by or competitive about similar projects, Hudson welcomes them with open arms. She believes the story of the Mandelas should be told "as many times as the world needs to hear it."

"I just feel like any way we can put a story out there, the more the better," Hudson says.

The real-life Winnie Mandela was not as charmed by the idea.

"I have absolutely nothing against Jennifer, but I have everything against the movie itself," she told CNN in 2011, lamenting that she "was not consulted."

"I am still alive, and I think that is a total disrespect to come to South Africa, make a movie about my struggle and call that movie some translation of a romantic life of Winnie Mandela," she said.

The film was given a warmer reception in Dallas last week, where Hudson was on hand to screen it as part of MegaFest, the first International Faith and Family Film Festival.

"This movie is in great hands and I think that was a perfect debut for it," says Hudson. "I am excited about it and grateful."